Borderline Amniotic Fluid Index in Late Pregnancy and its Relationship with Perinatal Outcome

Abstract

The volume of the amniotic fluid is an important indicator of fetal health during late pregnancy. Overt oligohydramnios is an established risk factor that is associated with unfavorable outcomes. This study sought to compare birth outcomes of pregnancies whose AFI is borderline and those whose AFI is normal at term (37–41) weeks.

A cross-sectional study of 105 singleton pregnancies was carried out. The participants were stratified into two cases, namely Borderline AFI (n=50) and Normal AFI (n=55). We analyzed the two groups on clinical outcomes, labor and delivery data, neonatal biometric parameters, Apgar scores, umbilical artery pH, and neonatal morbidity.

All baseline demographics were similar except that there was a greater percentage of preeclampsia in the borderline AFI group (14.0% vs. 3.6%). Borders AFI pregnancies had much greater labor induction (56.0% vs. 32.7%) and cesarean delivery due to fetal distress (20.0% vs. 7.3%). There were also reduced mean birth weight (3050 g vs. 3280 g), increased small-for-gestational-age (24.0% vs. 9.1%), reduced 1-minute Apgar (median eight vs. 9), and reduced umbilical artery pH (7.23 vs. 7.26) in the borderline group of neonates. AFI value had a positive relationship with the percentile of birth weight (r=0.32, p=0.001).

The statistically significant symptoms of borderline AFI during late pregnancy are a statistically significant rise in obstetric operations, restricted fetal growth, and worse neonatal outcomes, including a composite outcome of perinatal morbidity. The results indicate that borderline AFI is no longer a benign form of normal and should be placed under more careful antenatal examination.